2.2.2. VSPERF Design Document

2.2.2.1. Intended Audience

This document is intended to aid those who want to modify the vsperf code. Or to extend it - for example to add support for new traffic generators, deployment scenarios and so on.

2.2.2.2. Usage

2.2.2.2.1. Example Connectivity to DUT

Establish connectivity to the VSPERF DUT Linux host. If this is in an OPNFV lab following the steps provided by Pharos to access the POD

The followign steps establish the VSPERF environment.

2.2.2.2.2. Example Command Lines

List all the cli options:

$ ./vsperf -h

Run all tests that have tput in their name - phy2phy_tput, pvp_tput etc.:

$ ./vsperf --tests 'tput'

As above but override default configuration with settings in ‘10_custom.conf’. This is useful as modifying configuration directly in the configuration files in conf/NN_*.py shows up as changes under git source control:

$ ./vsperf --conf-file=<path_to_custom_conf>/10_custom.conf --tests 'tput'

Override specific test parameters. Useful for shortening the duration of tests for development purposes:

$ ./vsperf --test-params 'TRAFFICGEN_DURATION=10;TRAFFICGEN_RFC2544_TESTS=1;' \
                         'TRAFFICGEN_PKT_SIZES=(64,)' pvp_tput

2.2.2.3. Typical Test Sequence

This is a typical flow of control for a test.

../../../../_images/vsperf.png

2.2.2.4. Configuration

The conf package contains the configuration files (*.conf) for all system components, it also provides a settings object that exposes all of these settings.

Settings are not passed from component to component. Rather they are available globally to all components once they import the conf package.

from conf import settings
...
log_file = settings.getValue('LOG_FILE_DEFAULT')

Settings files (*.conf) are valid python code so can be set to complex types such as lists and dictionaries as well as scalar types:

first_packet_size = settings.getValue('PACKET_SIZE_LIST')[0]

2.2.2.4.1. Configuration Procedure and Precedence

Configuration files follow a strict naming convention that allows them to be processed in a specific order. All the .conf files are named NNx_name.conf, where NN is a decimal number and x is an optional alphabetical suffix. The files are processed in order from 00_name.conf to 99_name.conf (and from 00a_name to 00z_name), so that if the name setting is given in both a lower and higher numbered conf file then the higher numbered file is the effective setting as it is processed after the setting in the lower numbered file.

The values in the file specified by --conf-file takes precedence over all the other configuration files and does not have to follow the naming convention.

2.2.2.4.2. Configuration of PATHS dictionary

VSPERF uses external tools like Open vSwitch and Qemu for execution of testcases. These tools may be downloaded and built automatically (see Installation) or installed manually by user from binary packages. It is also possible to use a combination of both approaches, but it is essential to correctly set paths to all required tools. These paths are stored within a PATHS dictionary, which is evaluated before execution of each testcase, in order to setup testcase specific environment. Values selected for testcase execution are internally stored inside TOOLS dictionary, which is used by VSPERF to execute external tools, load kernel modules, etc.

The default configuration of PATHS dictionary is spread among three different configuration files to follow logical grouping of configuration options. Basic description of PATHS dictionary is placed inside conf/00_common.conf. The configuration specific to DPDK and vswitches is located at conf/02_vswitch.conf. The last part related to the Qemu is defined inside conf/04_vnf.conf. Default configuration values can be used in case, that all required tools were downloaded and built automatically by vsperf itself. In case, that some of tools were installed manually from binary packages, then it will be necessary to modify the content of PATHS dictionary accordingly.

Dictionary has a specific section of configuration options for every tool type, it means:

  • PATHS['vswitch'] - contains a separate dictionary for each of vswitches supported by VSPEF

    Example:

    PATHS['vswitch'] = {
       'OvsDpdkVhost': { ... },
       'OvsVanilla' : { ... },
       ...
    }
    
  • PATHS['dpdk'] - contains paths to the dpdk sources, kernel modules and tools (e.g. testpmd)

    Example:

    PATHS['dpdk'] = {
       'type' : 'src',
       'src': {
           'path': os.path.join(ROOT_DIR, 'src/dpdk/dpdk/'),
           'modules' : ['uio', os.path.join(RTE_TARGET, 'kmod/igb_uio.ko')],
           'bind-tool': 'tools/dpdk*bind.py',
           'testpmd': os.path.join(RTE_TARGET, 'app', 'testpmd'),
       },
       ...
    }
    
  • PATHS['qemu'] - contains paths to the qemu sources and executable file

    Example:

    PATHS['qemu'] = {
        'type' : 'bin',
        'bin': {
            'qemu-system': 'qemu-system-x86_64'
        },
        ...
    }
    

Every section specific to the particular vswitch, dpdk or qemu may contain following types of configuration options:

  • option type - is a string, which defines the type of configured paths (‘src’ or ‘bin’) to be selected for a given section:

    • value src means, that VSPERF will use vswitch, DPDK or QEMU built from sources e.g. by execution of systems/build_base_machine.sh script during VSPERF installation
    • value bin means, that VSPERF will use vswitch, DPDK or QEMU binaries installed directly in the operating system, e.g. via OS specific packaging system
  • option path - is a string with a valid system path; Its content is checked for existence, prefixed with section name and stored into TOOLS for later use e.g. TOOLS['dpdk_src'] or TOOLS['vswitch_src']

  • option modules - is list of strings with names of kernel modules; Every module name from given list is checked for a ‘.ko’ suffix. In case that it matches and if it is not an absolute path to the module, then module name is prefixed with value of path option defined for the same section

    Example:

    """
    snippet of PATHS definition from the configuration file:
    """
    PATHS['vswitch'] = {
        'OvsVanilla' = {
            'type' : 'src',
            'src': {
                'path': '/tmp/vsperf/src_vanilla/ovs/ovs/',
                'modules' : ['datapath/linux/openvswitch.ko'],
                ...
            },
            ...
        }
        ...
    }
    
    """
    Final content of TOOLS dictionary used during runtime:
    """
    TOOLS['vswitch_modules'] = ['/tmp/vsperf/src_vanilla/ovs/ovs/datapath/linux/openvswitch.ko']
    
  • all other options are strings with names and paths to specific tools; If a given string contains a relative path and option path is defined for a given section, then string content will be prefixed with content of the path. Otherwise the name of the tool will be searched within standard system directories. In case that filename contains OS specific wildcards, then they will be expanded to the real path. At the end of the processing, every absolute path will be checked for its existence. In case that temporary path (i.e. path with a _tmp suffix) does not exist, then log will be written and vsperf will continue. If any other path will not exist, then vsperf execution will be terminated with a runtime error.

    Example:

    """
    snippet of PATHS definition from the configuration file:
    """
    PATHS['vswitch'] = {
        'OvsDpdkVhost': {
            'type' : 'src',
            'src': {
                'path': '/tmp/vsperf/src_vanilla/ovs/ovs/',
                'ovs-vswitchd': 'vswitchd/ovs-vswitchd',
                'ovsdb-server': 'ovsdb/ovsdb-server',
                ...
            }
            ...
        }
        ...
    }
    
    """
    Final content of TOOLS dictionary used during runtime:
    """
    TOOLS['ovs-vswitchd'] = '/tmp/vsperf/src_vanilla/ovs/ovs/vswitchd/ovs-vswitchd'
    TOOLS['ovsdb-server'] = '/tmp/vsperf/src_vanilla/ovs/ovs/ovsdb/ovsdb-server'
    

Note: In case that bin type is set for DPDK, then TOOLS['dpdk_src'] will be set to the value of PATHS['dpdk']['src']['path']. The reason is, that VSPERF uses downloaded DPDK sources to copy DPDK and testpmd into the GUEST, where testpmd is built. In case, that DPDK sources are not available, then vsperf will continue with test execution, but testpmd can’t be used as a guest loopback. This is useful in case, that other guest loopback applications (e.g. buildin or l2fwd) are used.

Note: In case of RHEL 7.3 OS usage, binary package configuration is required for Vanilla OVS tests. With the installation of a supported rpm for OVS there is a section in the conf\10_custom.conf file that can be used.

2.2.2.4.3. Configuration of TRAFFIC dictionary

TRAFFIC dictionary is used for configuration of traffic generator. Default values can be found in configuration file conf/03_traffic.conf. These default values can be modified by (first option has the highest priorty):

  1. Parameters section of testcase definition
  2. command line options specified by --test-params argument
  3. custom configuration file

It is to note, that in case of option 1 and 2, it is possible to specify only values, which should be changed. In case of custom configuration file, it is required to specify whole TRAFFIC dictionary with its all values or explicitly call and update() method of TRAFFIC dictionary.

Detailed description of TRAFFIC dictionary items follows:

'traffic_type'  - One of the supported traffic types.
                  E.g. rfc2544_throughput, rfc2544_back2back,
                  rfc2544_continuous or burst
                  Data type: str
                  Default value: "rfc2544_throughput".
'bidir'         - Specifies if generated traffic will be full-duplex (True)
                  or half-duplex (False)
                  Data type: str
                  Supported values: "True", "False"
                  Default value: "False".
'frame_rate'    - Defines desired percentage of frame rate used during
                  continuous stream tests.
                  Data type: int
                  Default value: 100.
'burst_size'    - Defines a number of frames in the single burst, which is sent
                  by burst traffic type. Burst size is applied for each direction,
                  i.e. the total number of tx frames will be 2*burst_size in case of
                  bidirectional traffic.
                  Data type: int
                  Default value: 100.
'multistream'   - Defines number of flows simulated by traffic generator.
                  Value 0 disables multistream feature
                  Data type: int
                  Supported values: 0-65536 for 'L4' stream type
                                    unlimited for 'L2' and 'L3' stream types
                  Default value: 0.
'stream_type'   - Stream type is an extension of the "multistream" feature.
                  If multistream is disabled, then stream type will be
                  ignored. Stream type defines ISO OSI network layer used
                  for simulation of multiple streams.
                  Data type: str
                  Supported values:
                     "L2" - iteration of destination MAC address
                     "L3" - iteration of destination IP address
                     "L4" - iteration of destination port
                            of selected transport protocol
                  Default value: "L4".
'pre_installed_flows'
               -  Pre-installed flows is an extension of the "multistream"
                  feature. If enabled, it will implicitly insert a flow
                  for each stream. If multistream is disabled, then
                  pre-installed flows will be ignored.
                  Data type: str
                  Supported values:
                     "Yes" - flows will be inserted into OVS
                     "No"  - flows won't be inserted into OVS
                  Default value: "No".
'flow_type'     - Defines flows complexity.
                  Data type: str
                  Supported values:
                     "port" - flow is defined by ingress ports
                     "IP"   - flow is defined by ingress ports
                              and src and dst IP addresses
                  Default value: "port"
'flow_control'  - Controls flow control support by traffic generator.
                  Supported values:
                     False  - flow control is disabled
                     True   - flow control is enabled
                  Default value: False
                  Note: Currently it is supported by IxNet only
'learning_frames' - Controls learning frames support by traffic generator.
                  Supported values:
                     False  - learning frames are disabled
                     True   - learning frames are enabled
                  Default value: True
                  Note: Currently it is supported by IxNet only
'l2'            - A dictionary with l2 network layer details. Supported
                  values are:
    'srcmac'    - Specifies source MAC address filled by traffic generator.
                  NOTE: It can be modified by vsperf in some scenarios.
                  Data type: str
                  Default value: "00:00:00:00:00:00".
    'dstmac'    - Specifies destination MAC address filled by traffic generator.
                  NOTE: It can be modified by vsperf in some scenarios.
                  Data type: str
                  Default value: "00:00:00:00:00:00".
    'framesize' - Specifies default frame size. This value should not be
                  changed directly. It will be overridden during testcase
                  execution by values specified by list TRAFFICGEN_PKT_SIZES.
                  Data type: int
                  Default value: 64
'l3'            - A dictionary with l3 network layer details. Supported
                  values are:
    'enabled'   - Specifies if l3 layer should be enabled or disabled.
                  Data type: bool
                  Default value: True
                  NOTE: Supported only by IxNet trafficgen class
    'srcip'     - Specifies source MAC address filled by traffic generator.
                  NOTE: It can be modified by vsperf in some scenarios.
                  Data type: str
                  Default value: "1.1.1.1".
    'dstip'     - Specifies destination MAC address filled by traffic generator.
                  NOTE: It can be modified by vsperf in some scenarios.
                  Data type: str
                  Default value: "90.90.90.90".
    'proto'     - Specifies deflaut protocol type.
                  Please check particular traffic generator implementation
                  for supported protocol types.
                  Data type: str
                  Default value: "udp".
'l4'            - A dictionary with l4 network layer details. Supported
                  values are:
    'enabled'   - Specifies if l4 layer should be enabled or disabled.
                  Data type: bool
                  Default value: True
                  NOTE: Supported only by IxNet trafficgen class
    'srcport'   - Specifies source port of selected transport protocol.
                  NOTE: It can be modified by vsperf in some scenarios.
                  Data type: int
                  Default value: 3000
    'dstport'   - Specifies destination port of selected transport protocol.
                  NOTE: It can be modified by vsperf in some scenarios.
                  Data type: int
                  Default value: 3001
'vlan'          - A dictionary with vlan encapsulation details. Supported
                  values are:
    'enabled'   - Specifies if vlan encapsulation should be enabled or
                  disabled.
                  Data type: bool
                  Default value: False
    'id'        - Specifies vlan id.
                  Data type: int (NOTE: must fit to 12 bits)
                  Default value: 0
    'priority'  - Specifies a vlan priority (PCP header field).
                  Data type: int (NOTE: must fit to 3 bits)
                  Default value: 0
    'cfi'       - Specifies if frames can or cannot be dropped during
                  congestion (DEI header field).
                  Data type: int (NOTE: must fit to 1 bit)
                  Default value: 0
'capture'       - A dictionary with traffic capture configuration.
                  NOTE: It is supported only by T-Rex traffic generator.
    'enabled'   - Specifies if traffic should be captured
                  Data type: bool
                  Default value: False
    'tx_ports'  - A list of ports, where frames transmitted towards DUT will
                  be captured. Ports have numbers 0 and 1. TX packet capture
                  is disabled if list of ports is empty.
                  Data type: list
                  Default value: [0]
    'rx_ports'  - A list of ports, where frames received from DUT will
                  be captured. Ports have numbers 0 and 1. RX packet capture
                  is disabled if list of ports is empty.
                  Data type: list
                  Default value: [1]
    'count'     - A number of frames to be captured. The same count value
                  is applied to both TX and RX captures.
                  Data type: int
                  Default value: 1
    'filter'    - An expression used to filter TX and RX packets. It uses the same
                  syntax as pcap library. See pcap-filter man page for additional
                  details.
                  Data type: str
                  Default value: ''
    'scapy'     - A dictionary with definition of a frame content for both traffic
                  directions. The frame content is defined by a SCAPY notation.
                  NOTE: It is supported only by the T-Rex traffic generator.
                  Following keywords can be used to refer to the related parts of
                  the TRAFFIC dictionary:
                       Ether_src   - refers to TRAFFIC['l2']['srcmac']
                       Ether_dst   - refers to TRAFFIC['l2']['dstmac']
                       IP_proto    - refers to TRAFFIC['l3']['proto']
                       IP_PROTO    - refers to upper case version of TRAFFIC['l3']['proto']
                       IP_src      - refers to TRAFFIC['l3']['srcip']
                       IP_dst      - refers to TRAFFIC['l3']['dstip']
                       IP_PROTO_sport - refers to TRAFFIC['l4']['srcport']
                       IP_PROTO_dport - refers to TRAFFIC['l4']['dstport']
                       Dot1Q_prio  - refers to TRAFFIC['vlan']['priority']
                       Dot1Q_id    - refers to TRAFFIC['vlan']['cfi']
                       Dot1Q_vlan  - refers to TRAFFIC['vlan']['id']
        '0'     - A string with the frame definition for the 1st direction.
                  Data type: str
                  Default value: 'Ether(src={Ether_src}, dst={Ether_dst})/'
                                 'Dot1Q(prio={Dot1Q_prio}, id={Dot1Q_id}, vlan={Dot1Q_vlan})/'
                                 'IP(proto={IP_proto}, src={IP_src}, dst={IP_dst})/'
                                 '{IP_PROTO}(sport={IP_PROTO_sport}, dport={IP_PROTO_dport})'
        '1'     - A string with the frame definition for the 2nd direction.
                  Data type: str
                  Default value: 'Ether(src={Ether_dst}, dst={Ether_src})/'
                                 'Dot1Q(prio={Dot1Q_prio}, id={Dot1Q_id}, vlan={Dot1Q_vlan})/'
                                 'IP(proto={IP_proto}, src={IP_dst}, dst={IP_src})/'
                                 '{IP_PROTO}(sport={IP_PROTO_dport}, dport={IP_PROTO_sport})',
'latency_histogram'
                 - A dictionary with definition of a latency histogram provision in results.
     'enabled'   - Specifies if the histogram provisioning is enabled or not.
     'type'      - Defines how histogram is provided. Currenty only 'Default' is defined.
                     'Default' - Default histogram as provided by the Traffic-generator.
'imix'           - A dictionary for IMIX Specification.
    'enabled'    - Specifies if IMIX is enabled or NOT.
    'type'       - The specification type - denotes how IMIX is specified.
                   Currently only 'genome' type is defined.
                   Other types (ex: table-of-proportions) can be added in future.
    'genome'     - The Genome Encoding of Pkt-Sizes and Ratio for IMIX.
                   The Ratio is inferred from the number of particular geneome characters
                   Genome encoding is described in RFC 6985. This specification is closest
                   to the method described in section 6.2 of RFC 6985.
                   Ex: 'aaaaaaaddddg' denotes ratio of 7:4:1 of packets sizes 64:512:1518.
                   Note: Exact-sequence is not maintained, only the ratio of packets
                   is ensured.
                   Data type: str
                   Default Value: 'aaaaaaaddddg'

2.2.2.4.4. Configuration of GUEST options

VSPERF is able to setup scenarios involving a number of VMs in series or in parallel. All configuration options related to a particular VM instance are defined as lists and prefixed with GUEST_ label. It is essential, that there is enough items in all GUEST_ options to cover all VM instances involved in the test. In case there is not enough items, then VSPERF will use the first item of particular GUEST_ option to expand the list to required length.

Example of option expansion for 4 VMs:

"""
Original values:
"""
GUEST_SMP = ['2']
GUEST_MEMORY = ['2048', '4096']

"""
Values after automatic expansion:
"""
GUEST_SMP = ['2', '2', '2', '2']
GUEST_MEMORY = ['2048', '4096', '2048', '2048']

First option can contain macros starting with # to generate VM specific values. These macros can be used only for options of list or str types with GUEST_ prefix.

Example of macros and their expansion for 2 VMs:

"""
Original values:
"""
GUEST_SHARE_DIR = ['/tmp/qemu#VMINDEX_share']
GUEST_BRIDGE_IP = ['#IP(1.1.1.5)/16']

"""
Values after automatic expansion:
"""
GUEST_SHARE_DIR = ['/tmp/qemu0_share', '/tmp/qemu1_share']
GUEST_BRIDGE_IP = ['1.1.1.5/16', '1.1.1.6/16']

Additional examples are available at 04_vnf.conf.

Note: In case, that macro is detected in the first item of the list, then all other items are ignored and list content is created automatically.

Multiple macros can be used inside one configuration option definition, but macros cannot be used inside other macros. The only exception is macro #VMINDEX, which is expanded first and thus it can be used inside other macros.

Following macros are supported:

  • #VMINDEX - it is replaced by index of VM being executed; This macro is expanded first, so it can be used inside other macros.

    Example:

    GUEST_SHARE_DIR = ['/tmp/qemu#VMINDEX_share']
    
  • #MAC(mac_address[, step]) - it will iterate given mac_address with optional step. In case that step is not defined, then it is set to 1. It means, that first VM will use the value of mac_address, second VM value of mac_address increased by step, etc.

    Example:

    GUEST_NICS = [[{'mac' : '#MAC(00:00:00:00:00:01,2)'}]]
    
  • #IP(ip_address[, step]) - it will iterate given ip_address with optional step. In case that step is not defined, then it is set to 1. It means, that first VM will use the value of ip_address, second VM value of ip_address increased by step, etc.

    Example:

    GUEST_BRIDGE_IP = ['#IP(1.1.1.5)/16']
    
  • #EVAL(expression) - it will evaluate given expression as python code; Only simple expressions should be used. Call of the functions is not supported.

    Example:

    GUEST_CORE_BINDING = [('#EVAL(6+2*#VMINDEX)', '#EVAL(7+2*#VMINDEX)')]
    

2.2.2.4.5. Other Configuration

conf.settings also loads configuration from the command line and from the environment.

2.2.2.5. PXP Deployment

Every testcase uses one of the supported deployment scenarios to setup test environment. The controller responsible for a given scenario configures flows in the vswitch to route traffic among physical interfaces connected to the traffic generator and virtual machines. VSPERF supports several deployments including PXP deployment, which can setup various scenarios with multiple VMs.

These scenarios are realized by VswitchControllerPXP class, which can configure and execute given number of VMs in serial or parallel configurations. Every VM can be configured with just one or an even number of interfaces. In case that VM has more than 2 interfaces, then traffic is properly routed among pairs of interfaces.

Example of traffic routing for VM with 4 NICs in serial configuration:

         +------------------------------------------+
         |  VM with 4 NICs                          |
         |  +---------------+    +---------------+  |
         |  |  Application  |    |  Application  |  |
         |  +---------------+    +---------------+  |
         |      ^       |            ^       |      |
         |      |       v            |       v      |
         |  +---------------+    +---------------+  |
         |  | logical ports |    | logical ports |  |
         |  |   0       1   |    |   2       3   |  |
         +--+---------------+----+---------------+--+
                ^       :            ^       :
                |       |            |       |
                :       v            :       v
+-----------+---------------+----+---------------+----------+
| vSwitch   |   0       1   |    |   2       3   |          |
|           | logical ports |    | logical ports |          |
| previous  +---------------+    +---------------+   next   |
| VM or PHY     ^       |            ^       |     VM or PHY|
|   port   -----+       +------------+       +--->   port   |
+-----------------------------------------------------------+

It is also possible to define different number of interfaces for each VM to better simulate real scenarios.

Example of traffic routing for 2 VMs in serial configuration, where 1st VM has 4 NICs and 2nd VM 2 NICs:

         +------------------------------------------+  +---------------------+
         |  1st VM with 4 NICs                      |  |  2nd VM with 2 NICs |
         |  +---------------+    +---------------+  |  |  +---------------+  |
         |  |  Application  |    |  Application  |  |  |  |  Application  |  |
         |  +---------------+    +---------------+  |  |  +---------------+  |
         |      ^       |            ^       |      |  |      ^       |      |
         |      |       v            |       v      |  |      |       v      |
         |  +---------------+    +---------------+  |  |  +---------------+  |
         |  | logical ports |    | logical ports |  |  |  | logical ports |  |
         |  |   0       1   |    |   2       3   |  |  |  |   0       1   |  |
         +--+---------------+----+---------------+--+  +--+---------------+--+
                ^       :            ^       :               ^       :
                |       |            |       |               |       |
                :       v            :       v               :       v
+-----------+---------------+----+---------------+-------+---------------+----------+
| vSwitch   |   0       1   |    |   2       3   |       |   4       5   |          |
|           | logical ports |    | logical ports |       | logical ports |          |
| previous  +---------------+    +---------------+       +---------------+   next   |
| VM or PHY     ^       |            ^       |               ^       |     VM or PHY|
|   port   -----+       +------------+       +---------------+       +---->  port   |
+-----------------------------------------------------------------------------------+

The number of VMs involved in the test and the type of their connection is defined by deployment name as follows:

  • pvvp[number] - configures scenario with VMs connected in series with optional number of VMs. In case that number is not specified, then 2 VMs will be used.

    Example of 2 VMs in a serial configuration:

    +----------------------+  +----------------------+
    |   1st VM             |  |   2nd VM             |
    |   +---------------+  |  |   +---------------+  |
    |   |  Application  |  |  |   |  Application  |  |
    |   +---------------+  |  |   +---------------+  |
    |       ^       |      |  |       ^       |      |
    |       |       v      |  |       |       v      |
    |   +---------------+  |  |   +---------------+  |
    |   | logical ports |  |  |   | logical ports |  |
    |   |   0       1   |  |  |   |   0       1   |  |
    +---+---------------+--+  +---+---------------+--+
            ^       :                 ^       :
            |       |                 |       |
            :       v                 :       v
    +---+---------------+---------+---------------+--+
    |   |   0       1   |         |   3       4   |  |
    |   | logical ports | vSwitch | logical ports |  |
    |   +---------------+         +---------------+  |
    |       ^       |                 ^       |      |
    |       |       +-----------------+       v      |
    |   +----------------------------------------+   |
    |   |              physical ports            |   |
    |   |      0                         1       |   |
    +---+----------------------------------------+---+
               ^                         :
               |                         |
               :                         v
    +------------------------------------------------+
    |                                                |
    |                traffic generator               |
    |                                                |
    +------------------------------------------------+
    
  • pvpv[number] - configures scenario with VMs connected in parallel with optional number of VMs. In case that number is not specified, then 2 VMs will be used. Multistream feature is used to route traffic to particular VMs (or NIC pairs of every VM). It means, that VSPERF will enable multistream feature and sets the number of streams to the number of VMs and their NIC pairs. Traffic will be dispatched based on Stream Type, i.e. by UDP port, IP address or MAC address.

    Example of 2 VMs in a parallel configuration, where traffic is dispatched

    based on the UDP port.

    +----------------------+  +----------------------+
    |   1st VM             |  |   2nd VM             |
    |   +---------------+  |  |   +---------------+  |
    |   |  Application  |  |  |   |  Application  |  |
    |   +---------------+  |  |   +---------------+  |
    |       ^       |      |  |       ^       |      |
    |       |       v      |  |       |       v      |
    |   +---------------+  |  |   +---------------+  |
    |   | logical ports |  |  |   | logical ports |  |
    |   |   0       1   |  |  |   |   0       1   |  |
    +---+---------------+--+  +---+---------------+--+
            ^       :                 ^       :
            |       |                 |       |
            :       v                 :       v
    +---+---------------+---------+---------------+--+
    |   |   0       1   |         |   3       4   |  |
    |   | logical ports | vSwitch | logical ports |  |
    |   +---------------+         +---------------+  |
    |      ^         |                 ^       :     |
    |      |     ......................:       :     |
    |  UDP | UDP :   |                         :     |
    |  port| port:   +--------------------+    :     |
    |   0  |  1  :                        |    :     |
    |      |     :                        v    v     |
    |   +----------------------------------------+   |
    |   |              physical ports            |   |
    |   |    0                               1   |   |
    +---+----------------------------------------+---+
             ^                               :
             |                               |
             :                               v
    +------------------------------------------------+
    |                                                |
    |                traffic generator               |
    |                                                |
    +------------------------------------------------+
    

PXP deployment is backward compatible with PVP deployment, where pvp is an alias for pvvp1 and it executes just one VM.

The number of interfaces used by VMs is defined by configuration option GUEST_NICS_NR. In case that more than one pair of interfaces is defined for VM, then:

  • for pvvp (serial) scenario every NIC pair is connected in serial before connection to next VM is created
  • for pvpv (parallel) scenario every NIC pair is directly connected to the physical ports and unique traffic stream is assigned to it

Examples:

  • Deployment pvvp10 will start 10 VMs and connects them in series
  • Deployment pvpv4 will start 4 VMs and connects them in parallel
  • Deployment pvpv1 and GUEST_NICS_NR = [4] will start 1 VM with 4 interfaces and every NIC pair is directly connected to the physical ports
  • Deployment pvvp and GUEST_NICS_NR = [2, 4] will start 2 VMs; 1st VM will have 2 interfaces and 2nd VM 4 interfaces. These interfaces will be connected in serial, i.e. traffic will flow as follows: PHY1 -> VM1_1 -> VM1_2 -> VM2_1 -> VM2_2 -> VM2_3 -> VM2_4 -> PHY2

Note: In case that only 1 or more than 2 NICs are configured for VM, then testpmd should be used as forwarding application inside the VM. As it is able to forward traffic between multiple VM NIC pairs.

Note: In case of linux_bridge, all NICs are connected to the same bridge inside the VM.

Note: In case that multistream feature is configured and pre_installed_flows is set to Yes, then stream specific flows will be inserted only for connections originating at physical ports. The rest of the flows will be based on port numbers only. The same logic applies in case that flow_type TRAFFIC option is set to ip. This configuration will avoid a testcase malfunction if frame headers are modified inside VM (e.g. MAC swap or IP change).

2.2.2.6. VM, vSwitch, Traffic Generator Independence

VSPERF supports different VSwitches, Traffic Generators, VNFs and Forwarding Applications by using standard object-oriented polymorphism:

  • Support for vSwitches is implemented by a class inheriting from IVSwitch.
  • Support for Traffic Generators is implemented by a class inheriting from ITrafficGenerator.
  • Support for VNF is implemented by a class inheriting from IVNF.
  • Support for Forwarding Applications is implemented by a class inheriting from IPktFwd.

By dealing only with the abstract interfaces the core framework can support many implementations of different vSwitches, Traffic Generators, VNFs and Forwarding Applications.

2.2.2.6.1. IVSwitch

class IVSwitch:
  start(self)
  stop(self)
  add_switch(switch_name)
  del_switch(switch_name)
  add_phy_port(switch_name)
  add_vport(switch_name)
  get_ports(switch_name)
  del_port(switch_name, port_name)
  add_flow(switch_name, flow)
  del_flow(switch_name, flow=None)

2.2.2.6.2. ITrafficGenerator

class ITrafficGenerator:
  connect()
  disconnect()

  send_burst_traffic(traffic, time)

  send_cont_traffic(traffic, time, framerate)
  start_cont_traffic(traffic, time, framerate)
  stop_cont_traffic(self):

  send_rfc2544_throughput(traffic, tests, duration, lossrate)
  start_rfc2544_throughput(traffic, tests, duration, lossrate)
  wait_rfc2544_throughput(self)

  send_rfc2544_back2back(traffic, tests, duration, lossrate)
  start_rfc2544_back2back(traffic, , tests, duration, lossrate)
  wait_rfc2544_back2back()

Note send_xxx() blocks whereas start_xxx() does not and must be followed by a subsequent call to wait_xxx().

2.2.2.6.3. IVnf

class IVnf:
  start(memory, cpus,
        monitor_path, shared_path_host,
        shared_path_guest, guest_prompt)
  stop()
  execute(command)
  wait(guest_prompt)
  execute_and_wait (command)

2.2.2.6.4. IPktFwd

class IPktFwd:
    start()
    stop()

2.2.2.6.5. Controllers

Controllers are used in conjunction with abstract interfaces as way of decoupling the control of vSwtiches, VNFs, TrafficGenerators and Forwarding Applications from other components.

The controlled classes provide basic primitive operations. The Controllers sequence and co-ordinate these primitive operation in to useful actions. For instance the vswitch_controller_p2p can be used to bring any vSwitch (that implements the primitives defined in IVSwitch) into the configuration required by the Phy-to-Phy Deployment Scenario.

In order to support a new vSwitch only a new implementation of IVSwitch needs be created for the new vSwitch to be capable of fulfilling all the Deployment Scenarios provided for by existing or future vSwitch Controllers.

Similarly if a new Deployment Scenario is required it only needs to be written once as a new vSwitch Controller and it will immediately be capable of controlling all existing and future vSwitches in to that Deployment Scenario.

Similarly the Traffic Controllers can be used to co-ordinate basic operations provided by implementers of ITrafficGenerator to provide useful tests. Though traffic generators generally already implement full test cases i.e. they both generate suitable traffic and analyse returned traffic in order to implement a test which has typically been predefined in an RFC document. However the Traffic Controller class allows for the possibility of further enhancement - such as iterating over tests for various packet sizes or creating new tests.

2.2.2.6.6. Traffic Controller’s Role

../../../../_images/traffic_controller.png

2.2.2.6.7. Loader & Component Factory

The working of the Loader package (which is responsible for finding arbitrary classes based on configuration data) and the Component Factory which is responsible for choosing the correct class for a particular situation - e.g. Deployment Scenario can be seen in this diagram.

../../../../_images/factory_and_loader.png

2.2.2.7. Routing Tables

Vsperf uses a standard set of routing tables in order to allow tests to easily mix and match Deployment Scenarios (PVP, P2P topology), Tuple Matching and Frame Modification requirements.

The usage of routing tables is driven by configuration parameter OVS_ROUTING_TABLES. Routing tables are disabled by default (i.e. parameter is set to False) for better comparison of results among supported vSwitches (e.g. OVS vs. VPP).

+--------------+
|              |
| Table 0      |  table#0 - Match table. Flows designed to force 5 & 10
|              |  tuple matches go here.
|              |
+--------------+
       |
       |
       v
+--------------+  table#1 - Routing table. Flow entries to forward
|              |  packets between ports goes here.
| Table 1      |  The chosen port is communicated to subsequent tables by
|              |  setting the metadata value to the egress port number.
|              |  Generally this table is set-up by by the
+--------------+  vSwitchController.
       |
       |
       v
+--------------+  table#2 - Frame modification table. Frame modification
|              |  flow rules are isolated in this table so that they can
| Table 2      |  be turned on or off without affecting the routing or
|              |  tuple-matching flow rules. This allows the frame
|              |  modification and tuple matching required by the tests
|              |  in the VSWITCH PERFORMANCE FOR TELCO NFV test
+--------------+  specification to be independent of the Deployment
       |          Scenario set up by the vSwitchController.
       |
       v
+--------------+
|              |
| Table 3      |  table#3 - Egress table. Egress packets on the ports
|              |  setup in Table 1.
+--------------+